Updated for RC2a. Also updated the commenting to include a "// start..." and "// end..". Changes are sprinkled throughout the files, so save yourself the headache and please use a file comparer like KDiff3, WinMerge, etc!

Also added some changes of my own:
Change "Suburb" to "Address 2" in
Catalog>Includes>Languages>english.php
Catalog>Admin>Includes>Languages>english.php
Change "Post Code" to "Zip Code" in
Catalog>Includes>Languages>english.php
Catalog>Admin>Includes>Languages>english.php

If you want, you can also swap the order entry of address info to make it more familiar (at least for U.S.). Just find the chunks of POSTCODE code and move them below STATE:
from: Address, Zip, City, State
to: Address, City, State, Zip in:
Catalog>Admin>customers.php
Catalog>create_account.php
Catalog>Includes>Modules>checkout_new_address.php
Catalog>Includes>Modules>adress_book_details.php


More...